1. Field of the Invention
The present invention relates to an image processing apparatus and method, and more particularly, to an image processing apparatus and method capable of rapidly and accurately tracking a location of a certain target subject on a video image.
2. Description of the Related Art
In general, a digital image processing apparatus displays a video image on a display unit by using data of a video file stored in a recording medium. In particular, a digital photographing apparatus that is a type of digital image processing apparatus displays a video image on a display unit or stores a video file in a recording medium by using data obtained from light that is incident on an imaging device.
One function of the digital photographing apparatus is a tracking function for tracking a certain target subject on a video image. The tracking function is performed by determining a portion of a frame image, which is most similar to a template (reference image) that is smaller than the frame image, as a tracking area. Here, a template is an image including the whole or a portion of the target subject to be tracked.
FIG. 1 is a conceptual view for describing a tracking method of a conventional digital image processing apparatus.
Referring to FIG. 1, a template T is compared to each of a plurality of portions of one frame image Im a plurality of times.
For example, if the one frame image Im has a size of 320×240 and the template T has a size of 80×60, the one frame image Im may be divided into 43621 sub-images (43621.241×181) each having the same size as the template T. A sub-image most similar to the template T is found from among the sub-images on the one frame image Im and a portion corresponding to the most similar sub-image is determined as a tracking area. Thus, if the one frame image Im has a size of 320×240 and the template T has a size of 80×60, a similarity calculation should be performed a total of 43621 times between the template T and the sub-images in order to determine the tracking area on the one frame image Im.
If 30 frame images are displayed in 1 second, a time for displaying one frame image on a display unit is 33 msec., and thus the similarity calculation should be performed 43621 times in 33 msec. Accordingly, a specification of hardware of the digital image processing apparatus should be greatly increased in order to perform such a huge amount of calculations in such a short time, which necessarily causes a problem of, for example, high manufacturing costs.